1. Field of Invention
The present invention relates generally to the treatment of radioactive waste and in particular to processing waste water from nuclear power reactors and other sources of radioactive waste materials.
2. Description of the Related Art
The capability to isolate and manage specific radioactive isotopes is necessary for clean, safe, and secure radioactive waste management, which in turn is essential for the safe and cost-effective use of nuclear power. In nuclear power plants, radioactive isotopes leak into the primary and secondary water loops of light water nuclear reactors; this leakage is an unavoidable result of the decay of nuclear fuel as well as the nuclear activation (through exposure to radiation from the reactor core) of reactor components.
The concentration of particular radioactive isotopes in waste materials generally determines the waste classification of the waste material (for example, Class A, Class B, and Class C in the United States; or low, intermediate, or high level waste [LLW, ILW, or HLW] in other countries). The waste classification of waste material in turn delineates the storage and disposal requirements for that waste material. As a rule, waste material that receives a higher classification (such as Class B or Class C) faces stricter storage and disposal requirements, is more costly to manage, and can be legally stored in fewer locations. Therefore, it is desirable to limit the volume and amount of waste material that receives a higher classification by separating or removing from that waste material those specific radioactive isotopes that drive waste classification. In this regard, particularly desirable are systems, methods and processes for the separation of Cs-137, Sr-90, Ni-63, Tc-99, Am-241, Co-58, Co-60, and several isotopes of Uranium, for example. It would also be advantageous for the isotope-separation technology to also facilitate and work with technology for the processing of those specific radioactive isotopes for long-term storage or disposal, as for example through solidification or vitrification.
U.S. patent application Ser. No. 12/371,201, by the same inventor as the present general inventive concept, discloses isotope-specific media (ISM) to separate specific radioactive isotopes from radioactive waste materials.
Processed waste water must be substantially free of radioactive contaminants if it is to be released into the environment. The radioactive material extracted from the waste water during processing must be stable or in a form that can be stabilized for disposal in a way that meets disposal site requirements, particularly with respect to preventing the leaching out of radioactive contaminates by liquid water. Additionally, the volume of the waste must be minimized because of both the limited space available for disposal of radioactive waste and the high cost of its disposal. Accordingly there is a need for better ways of processing radioactive waste water containing suspended solids and dissolved ions from nuclear power reactors and other sources.